This invention relates to cleaning methods and apparatus, and more particularly relates to methods and means for cleaning and rinsing the interior surfaces of railway tank cars and the like.
It is well known in the prior art that a diversity of commodities are transported by land in railway tank cars, truck trailers, transport tankers, etc. Railway tank cars typically are constructed with a single manway entry disposed atop and at the longitudinal center thereof. Prior to being filled or loaded with a particular commodity, such a tank car must be throughly cleaned or rinsed, depending upon the circumstances, for health and safety reasons. Such cleaning and rinsing operations have heretofore been not only labor-intensive and time-consuming, but also hazardous.
It is also well known in the art that there frequently are stubborn deposits contained on the interior surfaces including the bulkheads and floor of tank cars and the like which necessitate the use of a high pressure fluid spray to dislodge such deposits. Typically, to accurately direct such high pressure fluid spray to successfully dislodge deposits and the like, manual intervention is required. As will, of course, be appreciated by those skilled in the art, having a worker enter a tank car through a manway and then spray the various interior surfaces of the tank car under limited maneuverability and lighting conditions subjects the worker to dangers of skin, eye, nose and throat irritation or poisoning attributable to unknown chemicals and contaminants, suffocation from fumes, and physical injury due to slippery surfaces and foreign obstacles and the like, and even from explosions.
There have been several attempts in the art to provide different varieties of robotic means or similar apparatus to improve the methodology for cleaning and washing the interior surfaces of tank cars and the like. For example, Hirose et al. disclose an apparatus for cleaning the inner surface of a tank in U.S. Pat. No. 5,392,798. The Hirose apparatus provides a pair of expansion links with each link having a rotary jet nozzle affixed at the end thereof. Driven by a driving shaft located outside of the tank, the degree of expansion of the pair of links enables the various tank surfaces to receive a jet spray from each of the nozzle pair. Each nozzle head is rotatable about its own axis and is also adaptable to orbit about the axial center of the pipe delivering fluid thereto.
In U.S. Pat. No. 3,895,756, Jaeger teaches a method and apparatus for cleaning vessels that includes a spray nozzle connected to swivel joints mounted on two perpendicular axes. An external mechanism actuates and controls the hydraulically-actuated rotation of the nozzle about the perpendicular axes.
Similarly, Bristol Equipment Company of Yorkville, Ill. provides a nozzle assembly, model TC-N1, which is designed for cleaning foreign and hazardous materials from tank cars. This device affords a longitudinal nozzle sweep of up to 186.degree. and a transverse sweep of up to 70.degree., with an adjustable nozzle speed of from 15 sec to one hour per sweep. Based upon Bristol Equipment's product brochure, this apparatus incorporates technology from U.S. Pat. Nos. 3,895,756; 4,133,210; 4,147,062; 4,262,533; 4,475,410; 4,479,393; 4,562,747; and Canadian Pat. No. 1,062,041.
It will be appreciated that while these developments in the art have helped minimize the necessity for using manual intervention for cleaning and washing tank cars and the like, several problems still remain. Practitioners in the art are unable to provide a suitably powerful fluid blast that can dislodge the contaminant film and deposits that regularly are found on tank car interior surfaces and the like. Furthermore, these practitioners are generally unable to avail themselves of an apparatus which direct such a powerful fluid spray toward such interior surfaces with an acceptable accuracy and efficiency to avoid wasting water and other fluids, and to avoid an undue accumulation of washer fluid and dislodged a deposits in the bottom of a tank car. Indeed, the elongated configuration of a conventional tank car, not to mention such obstacles as standpipes and valve rods, are particularly difficult to reach and clean.
Significant improvements in the art have been made by the present inventor in U.S. Pat Nos. 5,352,298 and 5,518,553. U.S. Pat No. 5,352,298 teaches an apparatus and method for cleaning and stripping residue, contaminants, debris, etc. from the interior surfaces of tank cars and the like with a X-frame assembly with a pivotally attached swivel support assembly. The swivel support assembly is pivotally attached to a K-frame assembly which includes a plurality of arms interconnected with spray nozzles capable of being directed proximal to every interior surface. U.S. Pat No. 5,518,553 teaches a cleaning apparatus and method configured to reach every interior surface of a substantially vertical storage tank and the like. A fully maneuverable assembly is disclosed that inherently coordinates and synchronizes hydraulically-driven rotation of a vertical pole disposed on the floor of a storage tank with the hydraulically-driven rotation of a spray bar disposed at the remote end of a boom assembly. Close proximity of the spray to the internal surfaces is controlled by hydraulically operated cylinders contained on a rotor assembly.
The multiple nozzle devices known in the art, of course, distribute and diminish the trust obtainable from suitable commercially available pumps among the various nozzles. Using electrically-driven pumps to inject high-pressure cleaning and wash fluid such as water introduces safety hazards that may cause fire or explosion. Hydraulic pumps require cumbersome hoses and are not as compact, portable and versatile as pneumatic pumps. Single nozzle nozzles which are presently available in the art are unable to deliver a sufficiently high-pressure fluid spray against the various interior tank car surfaces to allow for the effective and thorough purging of even stubborn debris and deposits therefrom.
Furthermore, practitioners in the art have heretofore been unable to remotely clean and wash the interior of tank cars and the like with a device that provides a powerful orbital fluid spray that reaches all of the surfaces including end caps and the like which may be as far away from the nozzle as 20 feet In addition, it would be advantageous if there were available in the art a sufficiently portable and self-contained apparatus that could be readily hanged from a common wash-rack hoist and the like.
Accordingly, these limitations and disadvantages of the prior art are overcome with the present invention, and improved means and techniques are provided which are useful for cleaning and washing the interior of tank cars and the like.